Trichomonas vaginalis is an anaerobic, parasitic flagellated protozoan that is the causative agent of trichomoniasis. It is the most common pathogenic protozoan infection of humans in industrialized countries. It is estimated by the World Health Organization (WHO) that 180 million infections are acquired annually worldwide. The estimates for North America alone are between 5 and 8 million new infections each year, with an estimated rate of asymptomatic cases as high as 50%.
Trichomoniasis is a sexually transmitted disease which can occur in males and females. Symptoms of T. vaginalis typically experienced in women include: Vaginitis—itching, burning, and inflammation of the vagina; Cervicitis—inflammation of the cervix; Urethritis—inflammation of the urethra; or a green/yellow, frothy vaginal discharge. In addition, the infection may cause discomfort during intercourse and urination, as well as irritation and itching of the female genital area. In rare cases, lower abdominal pain can occur. Symptoms in women usually appear within 5 to 28 days of exposure.
Most men with trichomoniasis do not exhibit signs or symptoms. Although rare, some men may temporarily have an irritation inside the penis, mild discharge, or slight burning after urination or ejaculation.
There are several known ways to diagnose and detect Trichomoniasis. One classic form of detection is the pap smear, which displays a transparent “halo” around the superficial cell nucleus from samples of infected individuals. However, Trichomoniasis is rarely detected by studying discharge or with a pap smear because of the low sensitivity associated with this form of detection. T. vaginalis was traditionally diagnosed via a wet mount, in which “corkscrew” motility was observed. In women, a doctor may collect a specimen during a pelvic examination by inserting a speculum into the vagina and using a cotton-tipped applicator to collect a sample. The sample is then placed onto a microscopic slide and sent to a laboratory for analysis. However, detection via wet mount is less sensitive than newer methods such as rapid antigen testing and transcription-mediated amplification. Huppert et al., CID 2007:45 p. 194. These newer methods have greater sensitivity, but are not in widespread use.
Currently, the most common method of laboratory analysis is via overnight culture of the T. vaginalis organism. Sood, et al., Indian J. Med. Res. 125, April 2007, pp. 567-571; Ohlemeyer, et al., Journ. Of Ad. Health, 22:3 pp. 205-208 (March 1998). However, the presence of T. vaginalis can also be diagnosed by PCR, using the primers L23861 Fw and Rev. Sichirm, et al., Journ. Of Microbiological Methods, Vol. 68:2, pp. 243-247, (February 2007).
Thus, new diagnostic techniques aimed at more reliably and accurately detecting T. vaginalis are desired.